A flowing gas, such as an exhaust from a motor and an engine, creates a noise and can be considered to be noise pollution and also has some back pressure with respect to the pressure of the gas in the engine. For example, an internal combustion engine, such as a gasoline engine or a diesel engine or a kerosene engine, has an exhuast gas. The exhaust gas, directly, from the internal combustion engine produces considerable noise. In order to decrease this noise, there is employed a muffler. Generally, a muffler comprises a chamber having an inlet and an outlet. The chamber is much larger in cross-sectional area than the cross-sectional area of the inlet or the cross-sectional area of the outlet. Further, the volume of the chamber is much greater than the volume of the inlet tube and the volume of the outlet tube. Sometimes, a chamber may have baffles to reduce the noise. The speed of the exhaust gas upon entering the chamber from the inlet tube decreases in velocity so as to decrease the amount of noise. Further, the muffler and the chamber are made of metal so that heat energy is transmitted through the metal of the muffler or the metal surrounding the chamber so as to have a cooling effect and also with the cooling effect decrease the volume of the gas being exhausted from the chamber in comparison to the volume of the gas entering the chamber. One of the advantages of the muffler is to decrease the noise from the internal combustion engine and thereby decrease noise pollution. However, in the type of muffler just described, there is considerable back pressure with respect to the exhaust gas from the internal combustion engine. This back pressure decreases the efficiency of the internal combustion engine so that if the exhaust gas from the internal combustion engine were not under back pressure, the efficiency of the internal combustion engine would be greater than with the use of the muffler described.
In preparing for this patent application a patent search was made. The results of this patent search reveal the following related sound-suppressing devices of the following U.S. Pat. Nos.
981,770 PA1 1,383,150 PA1 1,489,422 PA1 2,788,078 PA1 2,353,914 PA1 2,944,623 PA1 2,957,537 PA1 3,374,857